Table 3 The point mutation in the QRDR of gyrA of nalidixic acid-resistant Salmonella.
Point mutation in the QRDR of gyrA | MIC (μg/mL)* | |
|---|---|---|
nalidixic acid | ciprofloxacin | |
nalidixic acid-resistant S. typhi | ||
Ser83→Phe (TCC→TTC) | ≥ 256 (9) | 0.06 (4), 0.125 (1), 0.25 (2), 0.5 (2) |
Asp87→Gly (GAC→GGC) | 128 (1) | 0.06 (1) |
Asp87→Asn (GAC→AAC) | 64 (2), ≥ 256 (1) | 0.06 (2), 0.25 (1) |
nalidixic acid-resistant S. paratyphi A | ||
Ser83→Phe (TCC→TTC) | ≥ 256 (59) | 0.25 (8), 0.5 (50), 1 (1) |
Ser83→Pro (TCC→CCC) | 32 (2) | 0.125 (1), 0.03 (1) |
nalidixic acid-resistant S. paratyphi C | ||
Ser83→Tyr (TCC→TAC) | ≥ 256 (1) | 0.125 (1) |